161357316121 has 2 divisors, whose sum is σ = 161357316122. Its totient is φ = 161357316120.

The previous prime is 161357316097. The next prime is 161357316143. The reversal of 161357316121 is 121613753161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87579891721 + 73777424400 = 295939^2 + 271620^2 .

It is a cyclic number.

It is not a de Polignac number, because 161357316121 - 2³⁷ = 23918362649 is a prime.

It is not a weakly prime, because it can be changed into another prime (161357316181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80678658060 + 80678658061.

It is an arithmetic number, because the mean of its divisors is an integer number (80678658061).

Almost surely, 2^161357316121 is an apocalyptic number.

It is an amenable number.

161357316121 is a deficient number, since it is larger than the sum of its proper divisors (1).

161357316121 is an equidigital number, since it uses as much as digits as its factorization.

161357316121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 37.

The spelling of 161357316121 in words is "one hundred sixty-one billion, three hundred fifty-seven million, three hundred sixteen thousand, one hundred twenty-one".